Waterproofing porous building material such as brick, concrete, wood, stone, and slate.

Product: Thompson's Water Seal

Surface Preparation:

Thompson's Water seal should only be applied to clean, dry surfaces that are sufficiently porous to allow full penetration of the product. Ensure that sufficient Thompson's Water seal is applied to mortar joints, in particular the junction between mortar and bricks or blocks. Thompson's Water seal should not be applied to recently sealed surfaces and any film forming coatings, for example, paint should be removed or allowed to weather for at least two years.

Any surface discoloration should be treated prior to the application of Thompson's Water seal or marks, stains or blemishes in the substrate will show through after treatment.

Ensure that surface and air temperature are above 5°C.

General substrate:

Ensure that the substrate is clean, dry and free from oil, grease and any other contamination such as moulds and fungal growth. Remove oily deposits by washing surfaces with white spirit. Any fungal deposits should be treated with either a proprietary fungicide, such as Thompson's mould & moss Killer, or diluted household bleach (1 part bleach : 4 parts water). Treated areas should be rinsed thoroughly with water. Allow to dry for at least two days.

As Thompson's Water seal will not fill cracks or gaps carry out any necessary repair work before its application.

Special substrates:

Concrete Curing mixed concrete should be laid by standard procedures and tamped down leaving an even but fairly rough surface.

In cool, calm weather conditions the concrete surface should be smoothed down with a float to produce a satisfactory finish. A spray coat of Thompson's Water seal should then be applied to the entire surface whilst the concrete is still wet. The concrete should then be allowed to dry.

When hot/windy weather conditions prevail a two stage procedure involving the use of Thompson's Water seal is recommended. After the concrete has been tamped down to provide a rough but fairly even finish a spray coating of Thompson's Water seal is applied and trowelled in the surface which is then smoothed down. This helps prevent cracking and checking (crazing) of the concrete. it also penetrates deep into the surface and helps control the evaporation rate of water. A second spray coat of Thompson's Water seal is then applied and the concrete allowed to dry.

When used as a concrete hardening agent Thompson's Water seal should be applied at a rate of 1 litre per 5 square metres.

Applications:

Thompson's Water seal may be applied by brush, roller, low pressure spray (under 200 psi) or poured on and allowed to settle naturally into the surface.

On horizontal surfaces, leave Thompson's Water seal for 15 minutes then redistribute any unabsorbed material to dry areas. When treating vertical surfaces start at the bottom and work upwards.

When spray application is used specific recommendations of equipment manufacturers or suppliers should always be observed.

In general, a two coat application is specified in all cases using the recommended coverage guidelines.

Coverage

Coverage rate will vary with the absorbency of the substrate. The coverage guidelines given below are the minimum recommended quantities required to give adequate waterproofing protection based on practical experience. older substrates in particular may require additional applications of Thompson's Water seal to ensure full repellency. A site trial is recommended.

Drying Time

Thompson's Water seal normally dries within 24 - 48 hours. Drying time will vary with absorbency of substrate and prevailing weather conditions. on masonry the second coat may be applied as soon as the first coat has soaked into the surface. on other substrates allow at least 24 hours between coats.

Clean Up

All equipment should be cleaned immediately after use with white spirit. Remove as much product as possible from equipment before washing.

Precautions/ First Aid

Observe and follow all warnings and instructions for use shown on the pack.

Keep out of reach of children.

Avoid contact with skin and eyes. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.

After contact with skin, wash immediately with plenty of soap and water or a proprietary skin cleanser. DO NOT USE SOLVENTS OR THINNERS/WHITE SPIRIT. Repeated exposure may cause skin dryness or cracking.

Ensure maximum ventilation during application and drying.

When applying in confined spaces, wear a face mask which is designed to prevent inhalation of solvent vapours.

When spraying, do not breathe spray, wear suitable respiratory equipment.

Specific health and safety data sheets are available on request.